This was pretty cool, using relatively simple mechanics to solve puzzles was nicely implemented imo.
I did get stuck initially until I realized you could swap characters in the pause menu, I was playing in the browser so I didn't even notice a pause screen until I saw the controls. The swapping characters I think is pretty cool, I just didn't interact with it as much. I basically just got almost all the way to the end of the hero's level, then swapped to the girl and finished her section, and then swapped back again.
I'm not sure if I reached the good or bad ending but I got to some sort of screen and then when I started again I had all the items but the hero character wasn't visible on the screen. I'd suggest investigating that unless its some intentional commentary on the fact that the hero died.
I think this could be expanded upon for an interesting game, so keep up the good work!